Extract OAuth2AccessTokenFetcher interface.

components/policy/core/common/cloud/cloud_policy_client_registration_helper.cc

Index: components/policy/core/common/cloud/cloud_policy_client_registration_helper.cc
diff --git a/components/policy/core/common/cloud/cloud_policy_client_registration_helper.cc b/components/policy/core/common/cloud/cloud_policy_client_registration_helper.cc
index 86bf530e2227faaf9c9b04839e29fc12fcad75fc..27878237ef2c8e8f71d8fdc8a839080404f538c4 100644
--- a/components/policy/core/common/cloud/cloud_policy_client_registration_helper.cc
+++ b/components/policy/core/common/cloud/cloud_policy_client_registration_helper.cc
@@ -19,7 +19,7 @@
 
 #if !defined(OS_ANDROID)
 #include "google_apis/gaia/oauth2_access_token_consumer.h"
-#include "google_apis/gaia/oauth2_access_token_fetcher.h"
+#include "google_apis/gaia/oauth2_access_token_fetcher_impl.h"
 #endif
 
 namespace policy {
@@ -134,7 +134,7 @@ void CloudPolicyClientRegistrationHelper::LoginTokenHelper::FetchAccessToken(
   // Start fetching an OAuth2 access token for the device management and
   // userinfo services.
   oauth2_access_token_fetcher_.reset(
-      new OAuth2AccessTokenFetcher(this, context));
+      new OAuth2AccessTokenFetcherImpl(context));
   std::vector<std::string> scopes;
   scopes.push_back(GaiaConstants::kDeviceManagementServiceOAuth);
   scopes.push_back(kServiceScopeGetUserInfo);
@@ -143,7 +143,8 @@ void CloudPolicyClientRegistrationHelper::LoginTokenHelper::FetchAccessToken(
       gaia_urls->oauth2_chrome_client_id(),
       gaia_urls->oauth2_chrome_client_secret(),
       login_refresh_token,
-      scopes);
+      scopes,
+      this);
 }
 
 void CloudPolicyClientRegistrationHelper::LoginTokenHelper::OnGetTokenSuccess(